i just bought Dx3's magnaflow mufflers and im about to get them installed this weekend. i searched and some guys do 2.5 piping and some do 2.25 piping. what are the pros and cons of each? i plan on staying NA for a while if that factors into anything. thanks.

 

anyone? i know 2.25 and 2.5 is what most people get, whats the pros and cons of each??

 

there's not much difference between the two. 2.5" piping might have a slightly throater sound.

keep in mind that the inlet pipe for the magnflows are 2.25" so going larger won't do much. I suggest getting mendrel bends in your piping to get the best air flow. I believe the stock piping is 2.25"

I also have some magnaflows that are waiting to be installed and plan on going with 2.25" straight piping and replace both 10 year old cats.

FYI, turbo engines would require 3" piping.

 

ahh thanks again cloud. 2.25 sounds good then, mandrel bent for sure! what are you replacing the cats with? are you still going to be able to pass CA smog?

 

I would like to replace my cats with just regular new ones. I should have no problems passing emissions...probably do better! I have some rattling and noises down there so my cats are definately near the end of the line. I don't think hi-flow cats are legal in cali.

Make sure you tell the installer to position the exhausts the way you want them. For me, I prefer to them pointing straight out, parallel...none of that angled exhaust look. I also would install them tucked..meaning 1 or 2 finger gap underneath the bumper and the tips almost flush with the bottom of the bumper lines. good luck and post up some pics when they are installed!

 

thanks for all the advice! i will definatly get some pics up when they are done. i get the mufflers tomorrow and i get paid tomorrow but i go on vacation monday. i dont know if i will have time to get them done before i leave

 

for NA- Dual exhaust= 2.25" Single exhaust= 2.5"

 

thanks!


also should i go with a y-pipe or x-pipe? whats going to give me the best performance gains? i want to do this right the first time.

 

i think x-pipes are for SC400's only. y-pipes would work for your car. in our cars, the header is located on one side of the engine, goes to a single pipe, then to a cat, then to another cat, the branches out into two pipes to the mufflers.

 

i called just about every local place around me and no one does mandrel besides valley muffler in la puente and mikes in el monte. im goin on vacation for a week so when i get back im going to get bids from both of those places.

 

There is a bigger difference in 2.25 VS 2.50 than you would think. If I was you and you are staying N/A I would go with 2.25 for many reasons. Also the stock pipe size varies from 2.25 to 1.5 ( its flat pressed for clearence some places ) at least on the SC400.

Here's a flow comparison of different pipe sizes.
Straight Pipe CFM :

2.0 " = 283 CFM

2.25 " = 365 CFM

2.5" = 521 CFM

 

while on the exhaust topic, does anyone know the smog requirements for a 94 in CA? how often does it have to be done and so on? i heard somewhere if a vehicle is older then XXXX there is no smog law enforced?

 

You gotta smog a 94 for sure! By the way, the high-flo cats are legal in Cali. Check out planetsoarer.com for great info on the X-pipe set up.
Dave

 

thanks for the info jgscott. yeah I plan on going with 2.25" piping.

 

hi-flow cats are legal? do you mean somthing like this?:


http://www.hottexhaust.com/detail.asp?PRODUCT_ID=93535

If you know a place where we can buy hi-flow cats, please share